Along with fumigating the infested trains, including a fourth train on the N-line, the MTA has sent a bug-sniffing dog to inspect the remaining cars. The most worrying detail about the MTA’s bedbug infestation, though, may be that the conductor who found one of the bloodsucking beasts in her home hasn’t worked an N train in some time. “I could have picked it up on any train,” she toldthe Daily News.